If Zero Dark Thirty was the definitive film about America’s War on Terror, here’s the last word on its War on Drugs.

While not short on action, its focus on morally compromised ‘heroes’ makes it very much a thinking person’s thriller – as dense as it is tense.

Taking its name from the Mexican word for hitman, the film homes in on Emily Blunt’s FBI agent who, after a disastrous operation against a Mexican cartel, is recruited to join a shady government force.

Tasked with taking the fight south of the border, its chief ( Josh Brolin ) tells her their mission is to “dramatically overreact”.

From an opening scene in which a tank crashes into a living room to a truly shocking finale, Sicario delivers the goods, and then some, for action fans while offering a smart, subversive look at US drugs policy and the dubious character of its enforcers.

A key scene, in which the team breaches a traffickers’ tunnel, neatly highlights not just their physical but also moral descent.